1. Technical Field
The present invention relates to a power reception device, an electronic apparatus, and a non-contact power transmission system.
2. Related Art
In resent years, a non-contact power transmission technique has been attractive. The non-contact power transmission technique makes it possible to perform transmission of electric power by utilizing electromagnetic induction without using a metallic contact. As an application of the non-contact power transmission technique, a technique of charging a mobile phone or a home-house device (for example, a cordless handset for a telephone) has been heretofore offered.
JP-A-2006-60909 is an example of related art and discloses a power reception device including a secondary circuit 21, a voltage division circuit 251, and a power reception control device 2521 and 28. In the description, transmission of data to a power transmission device (primary side) from a power reception device (secondary side) is achieved by so-called a load modulation process. The power transmission device detects an induced voltage of a primary coil by means of a comparator so that it detects variation of a load condition of the power reception device (secondary side) due to interposition of a foreign object or transmission of data.
JP-A-11-164497 is another example of related art and discloses a protection circuit for preventing excessive heating of a secondary coil and an element in a power reception device due to an abnormality. The protection circuit includes, for example, a temperature sensor 8, a detection circuit 9 for detecting abnormal temperature, and a mechanical relay switch circuitry connected to both ends of secondary coil. It is preferable, in general, that an electronic apparatus or a circuit built therein (for example, a power reception device) has a simple structure. However, it is hard for a person skilled in the art to design a circuit having a simple structure.